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Related papers: The strong coupling, unification, and recent data

200 papers

The predictions of the MSSM are discussed in the light of recent LEP and SLD precision data. The full supersymmetric one loop corrections to the effective weak mixing angle, experimentally determined in LEP and SLD experiments, are…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. Dedes , A. B. Lahanas , K. Tamvakis

We assume that strong and electroweak interactions become strong at very high energies. With this assumption, we compute the low-energy gauge coupling constants $\alpha_i (m_Z)$ as a function of the cutoff scale, taking the supersymmetric…

High Energy Physics - Phenomenology · Physics 2009-09-29 T. Moroi , Hitoshi Murayama , T. Yanagida

We update our previous work on an analysis of the electroweak data by including new and partly preliminary data available up to the 1996 summer conferences. The new results on the Z partial decay widths into b and c hadrons now offer a…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kaoru Hagiwara , Dieter Haidt , Seiji Matsumoto

We obtain a determination of the strong coupling alpha_s in quantum chromodynamics, by comparing perturbative calculations for the short-distance part of the static energy with lattice computations. Our result reads…

High Energy Physics - Phenomenology · Physics 2012-11-21 Xavier Garcia i Tormo

The apparent unification of gauge couplings in Grand Unified Theories around 10$^{16}$ GeV is one of the strong arguments in favor of Supersymmetric extensions of the Standard Model. In this paper, an analysis of the measurements of the…

High Energy Physics - Phenomenology · Physics 2016-01-20 Dimitri Bourilkov

We present a determination of the strong coupling constant $\alpha_s(m_Z)$ using inclusive top-quark pair production cross section measurements performed at the LHC and at the Tevatron. Following a procedure first applied by the CMS…

High Energy Physics - Phenomenology · Physics 2017-12-06 Thomas Klijnsma , Siegfried Bethke , Günther Dissertori , Gavin P. Salam

The current phenomenological determinations of $\alpha_s(M_\tau)$ and $\alpha_s(M_Z)$ are shown to be only marginally consistent with the QCD evolution of the strong coupling constant between $M_Z$ and $M_\tau$. This motivates a revised…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. G. Steele , V. Elias

The unification of gauge couplings suggests that there is an underlying (supersymmetric) unification of the strong, electromagnetic and weak interactions. The prediction of the unification scale may be the first quantitative indication that…

High Energy Physics - Phenomenology · Physics 2011-07-19 D. Ghilencea , M. Lanzagorta , G. G. Ross

I derive conservative upper bounds on the supersymmetry breaking parameter $m_{1/2}$ as a function of the strong coupling in the Standard Supersymmetric Model (SSM) using gauge coupling unification. I find that over more than $99\%$ of the…

High Energy Physics - Phenomenology · Physics 2016-09-01 S. Kelley

The precision electroweak program, including weak neutral current (WNC), $Z$-pole, and high energy collider experiments, has been the primary prediction and test of electroweak unification. It has established that the standard model (SM) is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Paul Langacker

We examine gauge coupling unification and prediction for $\alpha_s (M_Z)$ in minimal flipped SU(5) with gauge-mediated supersymmetry breaking. We include threshold corrections at weak scale, messenger scale and unification scale, and…

High Energy Physics - Phenomenology · Physics 2009-10-31 K. T. Mahanthappa , Sechul Oh

We present two determinations of the strong coupling \(\alpha_s\). The first one is from the static energy at three-loop accuracy, and may be considered an update of earlier determinations by some of us. The new analysis includes new…

Astrophysical tests of the stability of fundamental couplings, such as the fine-structure constant $\alpha$, are a powerful probe of new physics. Recently these measurements, combined with local atomic clock tests and Type Ia supernova and…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-13 C. J. A. P. Martins , A. M. M. Pinho , P. Carreira , A. Gusart , J. López , C. I. S. A. Rocha

We determine the value of the strong coupling $\alpha_\text{s}$ and study its running over a wide range of scales as probed by the dijet production process at hadron colliders, based on an NNLO QCD analysis of LHC dijet data. From a large…

There are two aspects to the 1995 summer update of the combined preliminary electroweak data from LEP and SLC. On the one hand, agreement between experiments and the Standard Model (SM) has improved for the line-shape and the asymmetry…

High Energy Physics - Phenomenology · Physics 2007-05-23 Kaoru Hagiwara

We update and extend a previous N$^3$LL$^\prime$+${\cal O}(\alpha_s^3)$ strong coupling determination from thrust data. In particular, we carry out a fit with data fully restricted to the dijet region seeking to minimize the potential…

High Energy Physics - Phenomenology · Physics 2024-05-24 Miguel A. Benitez-Rathgeb , André H. Hoang , Vicent Mateu , Iain W. Stewart , Gherardo Vita

The status of coupling constant unification (with and without a unification of Yukawa couplings) is discussed. Uncertainties associated with the input coupling constants, $m_{b}$ and $m_{t}$, threshold corrections at the low and high scale,…

High Energy Physics - Phenomenology · Physics 2007-05-23 Nir Polonsky

The commonly accepted notion of a weak unified coupling $\alpha_X \approx 0.04$, based on the assumption of the MSSM--spectrum, is questioned. It is suggested that the four--dimensional unified string coupling should very likely have an…

High Energy Physics - Phenomenology · Physics 2009-10-28 K. S. Babu , Jogesh C. Pati

Using recent CLEO III results for the cross section for $e^+e^- \to {\rm hadrons}$ at seven centre-of-mass energies between 6.964 and 10.538 GeV, we derive a value for the strong coupling constant…

High Energy Physics - Phenomenology · Physics 2008-11-26 Johann H. Kuhn , Matthias Steinhauser , Thomas Teubner

The current world-average of the strong coupling at the Z pole mass, $\alpha_s(m^2_{Z}) = 0.1181 \pm 0.0013$, is obtained from a comparison of perturbative QCD calculations computed, at least, at next-to-next-to-leading-order accuracy, to a…

High Energy Physics - Phenomenology · Physics 2016-06-29 David d'Enterria